In present-day mountain bike races ascents and descents, which are mostly of a fairly steep nature, alternate. In order to be able to counterbalance the bicycle specifically during such steep descents, it is necessary for the rider to be able to shift his bottom free from any obstacles behind the saddle in the direction of the rear axle. In the past, for this purpose, in particular when fairly long descents were involved, the rider lowered the seat post in the seat tube of the bicycle and fixed it there. As a result of the freedom obtained between saddle and bottom, it was now possible for the rider to shift his bottom behind the saddle without any problems. However, the lowering of the seat post in the frame could only be made by the rider by making an intermediate stop. This cost valuable time in a race so that these intermediate stops were abandoned, the distance between saddle and bottom bracket was therefore not reduced and it was therefore accepted that on steeper descents, the rider possibly got caught on the rear edge of the saddle. Under adverse conditions, getting caught on the rear edge of the saddle leads to a fall.